In the course of smelting, refining and casting of metal, samples for analyses are frequently taken in order to collect information on the molten metal. As the sampler for molten metal, there have been known (1) samplers which take in molten metal by virtue of molten metal head (pressure); (2) combination type sampler combining an iron edit tube and a quartz tube which draw molten metal; (3) samplers which forcibly draw molten metal by pumping; (4) samplers which draw molten metal by means of a vacuum drawing pipe, etc.
All of these known samplers are practically used and each of them has its respective advantage, but all have in common the disadvantage that samples of different shapes and quantities cannot be taken simultaneously.
For instance, in the course of refining of steel, for the purpose of analysis of the steel composition (chemical analysis, such as wet analysis and instrumental analysis such as photospectrometry) relatively large samples are taken using samplers of the above type (1) or type (2). On the other hand, for analysis of gaseous ingredients in steel, smaller samples in the shape of a small vial or a long pencil-like stick (usually 6 mm in diameter) are taken using samplers of the above type (3) or type (4). It is not convenient to take samples for gas analysis with samplers of types (1) and (2) from the view point of operation efficiency, and taking samples for chemical analysis with samplers of types (3) and (4) is not proper from the view point of the amount of samples. Therefore, people are obliged to use separate samplers to get samples for both analysis for chemical composition and analysis of gases respectively. This inevitably increases the frequency of sampling, which has an undesirable influence on the steelmaking operation, and also the consumption of many sampling containers raises the steelmaking cost.
When samplers of type (1) and (2) are used, cavities and bubbles are easily formed as the molten metal sample solidifies and therefore the samples taken are not always sound. Samplers of type (3) and (4) must be handled carefully and therefore these samplers are not versatile.
Under the circumstances, this invention is directed to a sampling container and an apparatus with which sound samples of different forms for both wet analysis and gas analysis can be taken simultaneously and exactly by simple operation.
In one aspect, this invention provides a vacuum sampling container which comprises a smaller diameter cylindrical section and a large diameter cylindrical section coaxially connected in mutual communication and evacuated and sealed, the free end of said small diameter cylindrical section being provided with a portion thinned to the extent that it is broken when the vacuum sampling container is immersed in a molten metal.
In another aspect, this invention provides a sampler for molten metal comprising a vacuum sampling container comprising a first small diameter cylindrical section and a large diameter cylindrical section connected coaxially in mutual communication and evacuated and sealed, the free end of said first small diameter cylindrical section being provided with a portion thinned to the extent that it is broken by virtue of the heat and pressure of the molten metal when the vacuum sampling container is immersed in a molten metal; a protective tube housing said vacuum sampling container and having an opening at the end thereof corresponding to the free end of said vacuum sampling container; and a connecting means secured to said vacuum sampling container which connects the integral body of said vacuum sampling container and the protective tube to a supporting rod for the sampler.
Now the invention is described in detail with reference to the attached drawings.